Application of azo dyes



Patented May 6, 1930 JAMES BADDILEY, F BLAGKLEY, IIEAIICHESTEE, El'IG-LAIJD, ASSIG'NOR T0 BRITISH DYE$TUFFS CORPORATION, LIMITED, OF BLACKLEY, MANCHESTER, ENGLAND APPLEGATEON GT 5.130 DYEE N0 Drawing. Application filed December 3, 1327, Serial lilo. 231,582, and in Great Britain December 10, 1928.

This invention relates to certain improve ments which I have discovered in connection with the application of the azo dyes which can be made by combining the diazo coinpouncl oi paranitroaniline ortho-sulphonic acid, with any middle component, re-diazotizing and combining, eitherin alkaline or acid solution, with Q-arninob-naphthol-7- sulphonic acid or its N- alkyl, aryl or acyl derivatives. These dyestuffs have been known for a considerable time and have been described as dyestuils for dyeing cotton, but they have never come into use in the dyeing industries. 1 have now discovered that these dyestuffs possess a good allinity for artificial silk fibres composed of regenerated cellulose, and in particular that they have the valuable property of giving even dyeings on lab rics made from these regenerated cellulose silks. Various shades of blue can be obtained. These dyestuffs may be represented by the following formula:

wherein R represents a divalent naphthalene or benzene residue and it represents hydrogen, alkyl, aryl or acyl group.

The application of these dyestuffs for dye ing regenerated cellulose silks h s not hitherto been known, and the process according to my invention, whereby level blue shades on these fibres by the use of hitherto useless dyes can be obtained, is therefore of considerable te-ciinical value. Those who are concerned with the dyeing out goods made from regenerated cellulose silks, for example from viscose silk, are well aware that these fibres present special problems in dyeing because the avidity ot' the silk for dyestufis is frequently irregular. As a result oi this irregular avidity of the silk, the dyeings obtained frequently come out very uneven in depth of shade. T his is particularly the case when the dyeing is carried out with the usual substantive blue dyestuiis, for example with the bright blue dye obtained by coupling dianisidine with two molecules 0t 1 8-aminonaphthol-Q d-disuh phonic acid. T he dyeings which are obtained according to my invention are notably level in depth of shade, and l have therefore by my invention introduced a valuable technical application for dyestull's which have hitherto not been of service in the dyeing indu tries. The dyeing process is illustrated by the following example, but it must be understood that I do not limit myself to the conditions named therein:

The dyebath is made up from 3000 parts of water, a little soap and about parts of Glaubers salt and one part of the secondary disazo dye obtained in the known manner by combining diazotized paramitro anilineortho-sulphonic acid with alpha-naphthyb ainine, re-diazotizing and combining with 2 ainiilo-5-naphthol-Z-sulphonic acid in alkae line solution. One hundred parts of the sill: material to be dyed is entered into the bath, after which the bath is heated up nearly to the boil and. the dyeing carried out nearly at the boil for about one hour. The goods are then removed, rinsed oil and dried, the resulting dyeings being a level blue shade. It in the above example, a dye prepared by substituting; a sulphonated alpha-naplithylamino in place of alpha-naphthylamine is used (the dye in this case having as free acid the probable formula wherein hydrogen, alkyl, aryl and acyl groups are all represented by R) an equally advantageous dyed product is obtained.

Further examples illustrative of my invention are quoted in the following table:

Secondary disazo colour from diazotized para-nitroaniline-ortho-sulphonic acid combined With Shade on viscose silk Middle component End component Alpha-naphthyla- 2-ethylamino-5-naphthol7- Blue mine sulphonic acid (coupled alkaline) Alpha-naphthyla- 2-phenylamino-5-naphtho1-7- Blue mine sulphonic acid (coupled alkaline) 2-a min o-5-n a p h t h 0 l-7-s u l- Reddish blue m-arnino-p-cresolphonic acid (coulped alkaline) methyl ether 2-phenylamino-5-naphthol-7- Bright blue sulphonic acid (coupled alkaline) Z-acetylamino-fi-naphthol-7- sulphonic acid (coupled alkaline) 2-phenylamino-5-naphthol-7- sulphonic acid (coupled acid) Blue-violet Blue What I claim and desire to secure by Letters Patent is 1. The process of dyeing regenerated cellulose silks in level blue shades, which comprises dyeing such a silk with secondary disazo dyes obtained by coupling diazotized para-nitro aniline-ortho-sulphonic acid with an amine having the following formula H N-R- wherein R represents a naphthyl or phenyl residue, the said amine being capable of'coupling with diazo compounds to form a diazotizable amino azo compound, rediazotizing and coupling'witha compound of the type HOaS NHR in which hydrogen, alkyl, aryl and acyl :roups'arc all represented by R.

2. The process of dyeing regenerated cells: lose silks in level blue shades which comprises dyeing such a silk With a secondary disazo dye obtained by coupling diazotiaed paranitro aniline-ortho-sulph0nic acid with alpha-naphthylamine, rediazotizing the product and coupling with a compound of the type in which hydrogen, alkyl, aryl and acyl groups are all represented by R.

3. The process of dyeing regenerated cellulose silks in level blue shades which comprises dyeing such a silk with the secondary disazo dyestufi' obtained by coupling diazotized pin the free acid form of vnn N:N N:N

N0a SO3H OH where hydrogen and a sulphonic roup are represented by X, and in which hydrogen, alkyl, aryl and acyl groups are all represented by R.

6. Regenerated cellulose silks dyed in level blue shades with a secondary disazo dye obtained by coupling a diazotized para-nitroaniline-ortho-sulphonic acid with an amine having the probable formula E2NRi wherein R represents a phenyl or naphthyl residue, said amine being capable of coupling with diazo compounds to form a diazotizable amino azo compound, rediazotizing and coupling with a compound of the type HOsS- I d-R in which hydrogen, alkyl, aryl and acyl groups are all represented by R;

7. Regenerated cellulose silks dyed in level blue shades with a disazo dye obtained by diazotizing para-nitroaniline-ortho-sulphonic acid with an amine of the class consisting of alpha-naphthylamine and meta-amino paracresol-methyl ether, rediazotizing and coupling with a compound of the type I HO wherein R represents hydrogen, ethyl, phenyl or acetyl groups.

In testimony whereof I afdx my signature.

JAMES BADDILEY. 

